Production of hydrocarbons used as fuel or heavy oil components and chemicals from biomass are of increasing interests since they are produced from a sustainable source of organic compounds.
The ketoacid Levulinic acid (LA, 4-oxopentanoic acid) is one of many platform molecules that may be derived from biomass. It may be produced from both pentoses and hexoses of lignocellulosic material (see FIG. 1) at relatively low cost. Some of the advantages and drawbacks of using levulinic acid as a platform molecule relates to the fact that it is considered to be a reactive molecule due to both its keto and acid functionality.
Esters of levulinic acid have been suggested as fuel components as well as cold flow additives in diesel fuels, and, for example, the methyl and ethyl esters have been used as additives in diesel fuel. Gamma-valerolactone (GVL), which may be obtained by reduction of levulinic acid, has been used as a fuel additive in gasoline. Further reduction of GVL to 2-methyltetrahydrofuran (MTHF) provides a product that may be blended with gasoline of up to 60%. Alkyl valerates produced from levulinic acid have also been suggested as biofuels.
Levulinic acid has also been used for the production of liquid hydrocarbon fuels by a number of catalytic routes, including a method of producing a distribution of alkenes, the distribution centered around C12, involving converting aqueous GVL in a first reactor system to butenes followed by oligomerization in a second reactor over an acidic catalyst (for example, Amberlyst® 70).
GB 601,922 (to John George Mackay Bremner) discloses the preparation of methyl vinyl ketone by heating i.a. levulinic acid in the vapour phase at a temperature of from 450° C. to 650° C.
Consequently, there is a need for additional processes for upgrading levulinic acid and other ketoacids to higher molecular weight compounds, which are suitable for use as, for example, fuel or heavy oil components or chemicals or as components in the production of fuel or heavy oil components or chemicals. For example, there is a need for such additional processes, which reduce the processing costs by, for example, improving the yield of the desired components or chemicals and/or improving the life time of the catalyst.